Japanese Patent Application Publication No. 2005-330813 discloses an engine stop-and-start system, such as an idle reduction control system, as one type of these systems.
Specifically, the engine stop-and-start system is designed to start energization of a motor of a starter to rotate a pinion of the starter at the timing when an engine restart request occurs during a rotational speed of a crankshaft of an internal combustion engine, referred to simply as an engine, dropping based on automatic stop control of the engine.
The engine stop-and-start system is designed to predict the timing when the rotational speed of the crankshaft (ring gear) will be synchronized with the rotational speed of the pinion in consideration of a time required for the pinion to reach a position engageable with the ring gear. The engine stop-and-start system is also designed to determine the timing to start shifting of the pinion to the ring gear based on the predicted timing when the rotational speed of the ring gear will be synchronized with the rotational speed of the pinion.